Polyengine bipropeller drive



July 31 1945 c. R. wAsl-:lGE

POLYENGINE BIPROPELLER DRIVE Filed July 14, 1942 4 Sheets-Sheet l July 31, 1945- c. R wAsElGE POLYENGINE BIPROPELLER DRIVE Filed July 14, 1942 4 Sheets-Sheet 2 @www QN* July 31, 1945. c. R. wAsElGE 2,380,839

POLYENGINE BIPROPELLER DRIVE Filed July 14, 1942 `4 Sheets-Sheet 5 #frog/Yen July 31, 1945. c. R. wAsl-:IGE 2,380,889

POLYENGINE BIPROPELLER DRIVE Filed July l4, 1942 4 Sheets-Sheet 4 u w Il il I il w l s E i Q Il a l N N R Il s q A aww @a l /M/f/Vrae "aN m Piezas (Maf/0f .L/ Y Man Patented July 31, 1945 zssasss roLraNGTNn mraoraum Dawn Charles Raymond Waseige, Saint-Etienne, Loire, France; vested in the Alien Property Custodian Application July 14, 1942, sei-iai No. 459,935 1n nance .my 2s, 1941 2 Claimi. (Cl. 17o-135.6)

My invention has for its object to provide a polyengine and bipropeller group. Two-engine and two-propeller groups are known in which two coaxial propellers are driven in opposite directions, the nrst by one of the engines. the second by the other. These two engines rotate generally in opposite directions. On the other hand, the torques of the two propellers may only be mutually cancelled if they are equal at every instant. When an engine does not run the torque of the rotating propeller is no longer counterbalanced and unbalances the airplane, particularly in the case of a central two-engine group; the torque must be corrected through the controls; the propeller of the stopped engine exerts a substantial drag upon the forward motion, and the general iineness of the machine is decreased when only a part of the power is available.

On the other hand, in the case of variable pitch propellers, as the speeds of the two propellers are not constantly in the same ratio, two independent .controls must be provided for adiusting the pitch.

Iheobject of the present invention is, inter alla, to remedy, at least in part, the aforesaid failings and to increase the eiiiciency of the engine-propeller group and that of the aerodyne, particularly in caseof stopping of one of the engines oi the group. which may comprise any number of engines.

For this purpose, in a polyengine-bipropeller according to this invention, each of the engines is connected to both propellers, preferably rotating in opposite directions, so that each of these propellers is driven simultaneously by the various engines, through the medium of transmissimi means. inserted between each engine and the` propeller assembly, elements which are proper to this particular engine and allow the driving member of said elements to be stopped while permitting the rotation of the driven member.

In such conditions, whichever the stopped engine may be. both propellers continue -to be driven by the remaining power of the group and their torques remain in the same ratio. On the other hand the various engines may be engines rotating in the same direction.

In the ambit of this generic arrangement resulting from the generic inventive idea a number of ts are possible.

I'he said elements may consist in free-wheel devices or other one-way connections but, preferably, couplings controlled either by hand or automatically will be used, the automatic conof a member whose position is varied in accordance with a force which results from the engine operation, such as a force provided, for example, by a duid compressed by the engine, an electric current generated when the engine is running, etc.

In a particular embodiment the two propeller shafts are connected together by a motion reversing gear comprising an intermediate s haft and one of these propeller shafts is connected to all of the various engines.

A further object of the invention is to reduce the braking of two propellers on the running engines when one of the engines is not rotating, in order that the portion of power still available may drive these propellers at a speed approximating that of the engines of the group in normal use.

In a particular arrangement the means used therefor consist simply in using variable pitch propellers.

In another embodiment, there is inserted a.

variable speed gear between each engine and the set of the two-propellers in a known manner per se.

In this way xed pitch propellers may be used without overbraking the engines should one or several of them stop. This arrangement may also be combined with variable pitch propellers.

In another embodiment, the propeller set is driven through the medium of the planet-pinion carrier of a differential gear, one of whose sun wheels is driven by one half of the engines and the other by the second half, means being provided for stopping, preferably automatically, the

. sun wheel connected to the stopped engine.

Iwhich device would be connected simultaneously with the various engines, being, for example, driven from any one of the propeller shafts, whether the propellers rotate at the same speed or at different speeds.

trolbeingeected, for example, under the control Alike would be the conditions when the variable speed gearwhich is inserted between the two propellers and the various engines, is common to the whole oi' the latter, said gear being then driven from one of the driving members of the variable speed gem'.A

As examples which are in `nowise limitative several embodiments of the general arrangement which is the object of the present inventiony are schematically shown on the annexed drawings in the case of two engines.

In these drawings:

Fig. 1 shows a simple arrangement. i

Fig. 2 shows another embodiment s in which each propeller is driven by botnengines through the medium of a variable speed gear.

Pigs. 2 and 2b show the embodiment' of 2" with one enaine disconnected.

Fig. a snows snsiternstive tc rig. 2, in liicii-e 1 single variable speed gear is arranged betweenY the propellers and the various engines.

Flg.'4 shows a third modification' in which l'the engines are-connected to the propeller assembly by means of a differential gear.

Fig. 5 shows an alternative to the arran oi' 'they engine whatever may connected to the propellers.

gement be the way they are.

bers are indicated at 2l. The automatic control of this mechanism may be effected by means of a centrifugal governor of a known type. not shown, connected to both engines. this governor being, for example, driven from one of the elements of the on common to both engines.

When one of the engines has stopped, it is uncoupled by means of the mechanisms Il-Ie or 'Il-I1, vwhich may, if desired, be automatically controlled by known means, such as, for example,

h under the influence oi a movable member acted upon by a force resulting from the engine opera- In the example cf m. 1, ine concentric shafts l I -and 2 of the two propellers are connected to each other by a reversing gear here shown as comprising two bevel gears i and C respectively keyed opposite each other on said propeller shafts I, 2 and 'atv-lesstone bevel gear 1 meshing .with both said bevel gears and carried by a stationary shaft' l. The inner shaft l is provided with a. rearward extension'carrying a gear II in mesh with two othersmaller sears I2 and I3 arranged to rotate'asone with the driven part of couplings .|4. .Il, respectively, assumed here to be.claw clutches 'andprovided :with hand -controls I,: I'I

` the drivingipartof these clutches beingcarried by acorre'sp'onding shaftll, Il. respectively.1.1'he whole l"oi fthe above-mentioned 'elements' is, arranged in a 2l ifromgwhich projectv only 'the ends. of .the-two shafts I 0,. I l, which are .respec-x tively, connected totwo engines 2i, 22,by means er transmiten.' l# and atthe en'd of each of saidshafts. :f

cardan Jointstion, suchas a 'force produced by a iiuid main' tained under pressure by the engine, an electric,

rlcurrentl'generated by a generator driven by said enline. etc.

In the example of embodiment of Fig. 2, the

` two'4 propeller shafts are connected to each other Ibyzareverslng geardriven by means' of two re- .fducers, the same as in'the preceding example, the

only difference being that v'a-variable speed .gear

is inserted between the coupling= llaflla and the' corresponding reducer I2I I, -l I. 'These variable speed gears are here of the epicycllc type withcqnical planet pinions, and :each of them comprises a planet pinion carrier 3l. on the shaft 3| of which is keyed the pinion I2, 4Ilfoi.' theocrrosponding reducing gear. 'Ihe planet pinions' l! mesh simultaneously with sun wheels, Il of different4 diameters, the largerof'which, Il, ro.

tetes scene with che driven par: br the coupling Ila, Ila and the emailen, rotates as ons with a sleeve ll freelycarried by the shaft" and. on

. which is slldinglxsplined a,clutch sleeve 3l which .as may be shifted by means of a control mechanism 3l, 4l so as to be brought selectivdy'into mesh.

-either with a corresponding set of teeth II of the -pinion wheel I2. Ilorwith a nxed toothing .Il l

carried by,.the case. Preferably, ,as shown; the

i 49 control mechanism", ,Il of the variable speed 4; might also be independent.. f

It-isthus apparent thatthe two propellers to rotate atthe samespeed .and lnzopposite directlonsfwhlls sharing the total torque.applied to.. thezcommondriving shaft. constitutedihereby. part of the inner propeller-shaft. If both propellers have been designed to take the.

' same torque, at a common speed, such.as,', for ex-fample, that speed which corresponds `tothe nory .ands arecompelled by the reversinggearl, I, 'I;`

mal operation of the engines, accountbeing taken of their relative position, the two torques will be exactly balanced. On the other hand.thetwo engines rotate in the same direction.

Should any one of the 'engines stop. the W0.

:ofteeth'nofthecasell. I thus released from the planet pinion carrier 80 gear of one-of the engines 2i', n is coniugated, as t0 the. control ,mechanism Ila, llc of the. coupling Ila.' Ma oi' thel ther enginethough it,

- when cui engine., ai, lasciate' 'andere-'in gear,-each of,the clutch sleeves It of .the-two variable speed gears is in mesh with the claws Il of the corresponding pinions I2, I8. The latter. 'are thus directly connected' with the sun wheels :84, which are consequently made immovable with,

regardto the planet pinions. and each epicyclic assembly-.turns .as a' block., the :propellers being thus .directly driven by the engines. By unclutching one' of. the engines 2I,.2I,.that of the l co trois, Il of the variable speedgears which isassociated with the4 operated ,uncoupiing control I'Ia ,or lla, will disengage the corresponding clutch sleeve Il from the claws of pinion I2 or Il andv brings itlnto engagement with the nxed set The sun wheel I4 is which may thenrctsie relatively w 'seid sun wheel, and secured to the case. Speel reducing is consequently effected.

ofthe present applicant and entitled "Variable .pitch aerial propellers." This mechanism has beenschenriaticallysliivlrnamiitsvarlousmeni-v BY i proper designA one may sochoose the nducing gear ratio that the engine which remains in operation rotates ata speed approximating `its 'normal value, while the Dmpellers, the pitch of which may then be fixed, turn.at a slower speed.

Thersmay' be an advantage in using variable' pitch propellers, as this permits choosing areducing'ratioand a pitch which,by their combination, assures adaptation vof theplopellers to the various conditions of operation. Ifan automatic Vpitclieonti'olisetectec'llaymeans'ofacentrifugal governor, so that the Speed of the engines may be maintained substantially constant, two centrifugal governors, 42, of a known type, may be used. as here shown schematically, one of them being driven by one of the engines and the second by the other engine, only one of these governors 42 being in operation at any time; for example, as shown, these governors act upon the pitch varying mechanism 26 -by means of electric circuits 43 leading to a reversing switch 44 which will close the one or the other of said circuits in dependance on the running or the stopping of a given engine, for example on account of it being connected to the coupling control of one of the engines, so that it may be controlled thereby. i. e. here by the control Ila.

One may also use a single adjustable governor driven from any one of the propeller shafts, or again a single governor-adjustable or notconnected to each of the engines through the medium of free-wheel devices.

In the alternative embodiment shown in Fig. 3, there is used only one variable speed gear which is then common to the various engines. The propellers are connected to each other through a reversing gear, as in Figs. l and 2, andthe engines drive through transmission shafts and cardan devices, as in Figs. 1 and 2, couplings I4b and lib, similar to the couplings I4 and I5 of Fig. 1, and pinions I2b and I3b, similar to pinions I2 and I3, said pinions I2b and Ilb meshing with a common wheel 46 which is freely supported coaxially with the propellers and carries a set of teeth 41 meshing with conical planet pinions 4I supported by means of arms 49 on the inner propeller shaft I. Said planet pinions 48 gear besides with a smaller wheel 50 loose on the shaft I and on said wheel is slidingly keyed a clutching sleeve I having two sets of claws adapted to be brought by sliding motion of the sleeve 5I into engagement either with a set of claws 52 fast with the shaft I, or with a set of claws 53 fast with the case 20h. The operation of this variable speed gear is similar to that of the variable speed gear shown in Fig. 2. Shifting of the sleeve 5I is eifected by means of a control 54 connected by rods and links 55 to both unclutching controls lib and I1b so that uncoupling of any one of the engines causes the sleeve 5I to be brought into engagement with the claws 53.

This inodification, though simpler than that of Fig. 2, gives the same results as the latter and lends itself tothe same combinations. Moreover, if variable pitch propellers are used the pitch of which is automatically controlled by means of a centrifugal governor; only one centrifugal governor is needed. Fig. 3 shows a way of mounting the same. Said governor 56 is housed in the case zlib and carries a pinion 51 meshing with a pinion 58 integral with the wheel 45, i. e. the driving member of the variable speed gear consisting of the members 46 to 53.

In the modification of Fig. 4, the pinion 5 driving the reversing gear, by means of which the two propellers are again connected together, as in the preceding examples, is integrally connected with the planet pinion carrier 6| to partake of the rotation thereof, the conical planet pinion 52 meshing with two coaxial sun wheels 83, 54, which are of the same size and keyed on concentric shafts 65, B6, respectively. On these shafts are also secured toothed wheels 61 and 58, respectively, which mesh respectively with a pinion 69, keyed on the shaft coming from the engine 2|, and a pinion 1l, secured to the shaft coming from the engine 22. 'I'he gearinss 89-81 and 10-48 constitute reducing gears.

The assembly 52-45, thus constituted. forms a differential gear whose planet-carrier 5I rotates at a speed which is themean of the speeds of the sun wheels I3, 84. In case of stopping of any one of the engines, the planet-carrier -BI will rotate at a speedl which is the half of that of the sun wheel still rotating. The speed of the propellers is thus reduced by one half, and it will be necessary, the same as in the case of Fig. 1. that their pitch-may be varied, though the reason for doing so, in the present case, is to avoid racing of the remaining engine by increasing the pitch. In order to prevent the stopped engine from rotating in the opposite direction-to its nor' mal direction of rotation, this embodiment according to Fig. 4 is preferably completed by the provision of means to stop selectively the sun wheels of the diiierential gear. These means consist as shown in providing for each sun wheel a fixed cylinder 12 in which is slidingly guided a piston 1l carrying outside the cylinder a head 14 provided with sets of claws adapted to be brought into engagement with complementary sets of claws 1B provided on the corresponding pinion 69 or 10. The piston 13 is urged by a spring 11 tending to engage the head 14 with the claws 16 against the action on said piston of a fluid under pressure introduced into said cylinder through a pipe 18 from the oil circuit of the engine. Said piston 13' is further connected with the cylinder 12 by means of a torque limiting device 19. When the engine is in operation the fluid pressure drives the piston 13 against the action of the spring 11 so that the corresponding pinion 69 or 10 may freely rotate. As soon as the oil pressure is lowered, the spring 11 shifts the piston 13, whose 40 head 14 engages the claws 16, which stops the corresponding pinion i8 or 10 and, consequently. the sun wheel 83 or $4, the differential gear thus forming a reducing gear with a ratio 1/2 between the running engine and the propellers. The torque limiting device 19 reduces the impact at stopping.

Fig. 4 shows also a way of carrying out the pitch variable control for the propellers by means of a single centrifugal governor in order that the speed of the engine may remain constant. This governor is driven by a pinion 8| connected with the various shafts by means of trains of gears 82, 83, with the interposition of one-way couplings I4 for insuring that the governor will be driven only from the engine running at the greatest speed, so that it will continue to be driven should one of the engines f ail.

In the various embodiments above-described, the engines are shown inclined to the axis of the propellers and symmetrically arranged on each side of said axis. However, whatever which way the invention may otherwise have been carried out, these engines may also be arranged parallelly to said propeller axis, as shown in Fig. 5, one of them being then located forward of the other and the transmission shaft from the most removed engine being divided into two parts connected by means of cardan joints or the like with a short shaft supported in an intermediate bearing 85.

Obviously, the invention is in nowise limited to the details of the modifications shown and described, which are only indicated as examples.

Thus, instead of the various engines driving the same wheel keyed on one of the two propeller shafts which are connected together by a reversing gear, another wheel may'be provided onthe second propeller shaft, some of the engines driving the nrst of these wheels and the others :the second.

On the other hand, instead of connecting the two propeller shafts by means of areversing gear, these shafts may each carry a toothed wheel and these two wheels may be driven simultaneously by all the engines, the connection between the two wheels and each engine comprising for each wheel a supplementary reversing wheel if it is desired to have the two propeller shafts rotatingin opposite directions.

Moreover, in the case of the modillcations comprising variable speed gears, the latter may further comprise a special control adapted to be operated by the pilot without uncoupling 'the engine, such as on taking oil', for example.

Likewise, the device for driving a single centrifugal, which is shown in Fig. 4, may be applied to the embodiments oi' Figs. 2 and 3. This device shown in Fig. 4 with a single centrifugal governor may also be substituted with two govemors as per Fig. 3. the electric reversing appa-- ratus being then operated by the movement on one of the pistons 1l. Lastly, in the three cases of Figs. 2, 3 and 4. in view of using only a single centrifugal governor, the latter may be of an adjustable type and adapted to be driven by any one of the propeller shafts.

What I claim is:

1. In a power plant for a dual engined aircraft, the combination of a pair of co-axial shafts; gearing connecting said shafts; a propeller mounted on each shaft; a gear mounted on one of said shafts; two gears meshing with said gear;

apairofengineseachhavingsdrivingshaft: a changeapeed mechanism connected with each of said last mentioned gears; a clutch connecting each driving shaft with one of said change speed mechanisms; means to operate each of said change speed mechanisms independently: means to operate each of said clutches independently, a connection between the operating means for each clutch and the operating means for the change speed mechanism connected by the other clutch. so that when either clutch is unclutched the change speed mechanism of the other clutch is shifted to low speed.

l 2. In a power plant for a dual engined aircraft, the combination of a pair of co-axial shafts; gearing connecting ysaid shafts; f a propeller mounted on each shaft; vmeans for varying the pitch of the propellers; a gear mounted on one of said shafts; two` gears meshing with said gear; a pair of engines each having a driving shaft; a change speed mechanism connected with each of said last mentioned gears; a clutch connecting each driving shaft with one of said change speed mechanisms; means to operate each of said change speed mechanisms independently; means to operate each koi' said clutches independently, a connectionbetween the operating means for each clutch and the operating means for lthe speed change mechanism connected by the other clutch, so that when either clutch is unclutched the change speed mechanism of the other clutch is shifted to low speed; and means controlling the pitch varying means and actuated by the said gear on the one of the co-axial shafts.

CHARLES RAYMOND WABEIGE. 

